How do I sponsor a taxi stand?

When you see a taxi stand there should be a picture of a taxi car over it. When you press the building you receive a certain amount of game dollars, the building starts sparkling, and taxi departs from the stand with a dollar sign over it.
After you sponsored everything, make sure you quit Mary's city right by pressing Home button in the left lower corner of the screen. You can sponsor 3 buildings a day and a building in Mary's City can be sponsored only once in 24 hours.